Herbicidal thiolcarbamates

ABSTRACT

Novel N,N-dialkylthiocarbamates, in which the N-bonded alkyl radicals are different, are disclosed. The compounds are useful as herbicides.

United States Patent 1191 Tilles 1451 June 26, 1973 HERBICIDAL THIOLCARBAMATES [75] Inventor: Harry Tllles, El Cerrito, Calif.

[73] Assignee: Stauffer Chemical Company, New

York, N.Y.

221 Filed: Dec. 14, 1970 211 App]. No.: 98,075

Related U.S. Application Data [63] Continuation-impart of Ser. No. 888,821, Dec. 29,

1969, abandoned.

[52] U.S. Cl. 260/455 A, 71/100 [51] Int. Cl. C07c 155/08 [58] Field of Search 260/455 A; 71/100,

[56] References Cited UNITED STATES PATENTS 5/1967 Harman et al.. 71/100 7/1961 Harman et a]. 260/455 A OTHER PUBLICATIONS Cambi et al., Magnetism and Polymorphism of Inner Complex Salts etc., (1937) CA 32 p. 1989 (1938).

Primary Examiner-Lewis Gotts Assistant ExaminerG. Hollrah Attorney-Daniel C. Block, Edwin H. Baker, Albert J. Adamcik and Harry A. Pacini [5 7] ABSTRACT Novel N,N-dialkylthiocarbamates, in hich the N- bonded alkyl radicals are different, are disclosed. The compounds are useful as herbicides.

1 Claim, No Drawings 1 HERBICIDAL THIOLCARBAMATES This application is a continuation in part of my copending application, Ser. No. 888,821, filed Dec. 29,

1969, now abandoned.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The compounds of the present invention have the formula wherein R is a member selected from the group consisting of lower alkyl, preferably having one to six carbon atoms, halo-lower alkyl, preferably having one to six carbon atoms and benzyl; R is selected from the group consisting of methyl, ethyl, n-butyl, and allyl, and R;, is selected from the group consisting of isobutyl, butyl, and amyl. A preferred grouping of the compositions is that in which R is selected from the group consisting of alkyl containing one to six carbon atoms and halo-lower alkyl of one to six carbon atoms. The term halo used in describing the present invention encompasses the moieties chloro-, bromo-, iodo-, and fluoro-, and includes polyas well as mono-substituted.

In general, the method of the invention comprises contacting undesired vegetation or a locus to be protected with an effective or herbicidal amount of a composition having the formula above indicated.

DETAILED DESCRIPTION OF THE INVENTION Broadly, the compounds of the invention may be prepared by reacting a compound of the formula W R SCCI wherein R is as above indicated with a compound of the formula wherein R and R are as above indicated. The concentrations of the reactants employed are not particularly critical, although generally an excess of the amine will be employed. A suitable concentration will be from about 1.0 mol to about 2.5 mols of the amine per mol of thio acid halide. although additional quantities may be present.

The reactions are preferably carried out in a solvent for the reactants. Suitable solvents include water, ether, benzene, chloroform or tetrahydrofuran. Reactions of this type are normally exothermic so that the addition of heat is not required. In actuality, cooling is sometimes required to control the reaction rate.- The reaction will normally be carried out at a temperature of from about -l5 C to about 55 C. Pressures may be atmospheric. subatmospheric or greater than atmospheric, as desired.

The following examples illustrate methods by which the compounds of the invention can be made.

EXAMPLE 1 Preparation of S-methyl isobutylethylthiocarbamate About 10.6 grams of ethylisobutylamine, 10.6 grams of triethylamine, cc. of ethyl ether and 100 cc. of water are charged into a flask and l 1.1 grams of methyl chloro thiolformate are added over a five-minute period. The initial temperature is about 1 8.5 and is regulated by cooling. The mixture is stirred for about 15-20 minutes, by which time the reaction is substantially complete. The mixtue is then phase-separated and the ether phase is washed with dilute HCl and then with water. The ether phase is then dried over MgSO filtered and concentrated for a very short period of time on a rotary evaporator. The concentrate is then fractionally distilled through an 18 inch Podbielniak column to obtain S-methyl isobutylethylthiocarbamate. Structure is confirmed by elemental analysis. Anal. Calcd. for C H NOS: C, 54.81; H, 9.77; N, 7.99 Found: C, 55.12; H,l0.l7; N, 7.99

EXAMPLE 2 Preparation of S-ethyl ethylisobutylthiocarbamate The general procedure of Example 1 is repeated except that 10.6 grams of N-ethyl isobutylamine and 12.5 grams of ethyl chlorothiolformate is employed. There is obtained S-ethyl ethylisobutylthiocarbamate.

EXAMPLE 3 Preparation of S-Z-chloroethyl ethylisobutylthiocarbamate The general procedure of Example 1 is repeated except that 15.9 grams of 2-chloroethyl chlorothiolformate and 10.6 grams of N-ethylisobutylamine are employed.

EXAMPLE 4 Preparation of S-3-chloropropyl ethylisobutylthiocarbamate The general procedure of Example I is repeated, except that 10.4 grams of 3-chloropropyl chlorothiolformate and 6.4 grams of ethyl isobutylamine are employed.

EXAMPLE 5 Preparation of S-benzyl ethylisobutylthiocarbamate When the general procedure of Example 1 is re peated, except that 7.5 grams of N-ethylisobutylamine and 13.1 grams of benzyl chlorothiolformate are employed, there is obtained S-benzyl ethylisobutylthiocarbamate.

EXAMPLE 6 Preparation of S-butyl ethyl t-butylthiocarbamate The general procedure of Example 1 is repeated, except that 15.2 grams of butyl chlorothiolformate and 10.6 grams of ethyl t-butylamine are employed.

EXAMPLE 7 Preparation of S-3-chloropropyl methylamylthiocarbamate When the general procedure of Example 1 is repeated, except that 7.5 grams of N-methylamylamine and 11.2 grams of 3-chloropropyl chlorothiolformate are employed, there is obtained S-3-chloropropyl me- As previously indicated, the compositions of the invention are phytotoiric compounds which are useful and valuable in controlling various plant species.'Several of the compounds exhibit superiority with respect thylamyl thiocarbamate. 5. to particular plant species as compared with other simi- The following is a table of preferred compounds lar materials. Compounds 1 through were tested in which may be prepared according to the invention. the following manner.

' Seeds of crabgrass, annual bluegrass, watergrass, red TABLE I oats, pigweed, mustard and curly dock were planted in l. S-methyl ethylisobutylthiocarbamate 10 individual rows about one-half inch deep in sandy loam 2. S-ethyl ethylisobutylthiocarbamate soil contained in 8- 4 inch X 6- /2 inch X 234 inch flats. 3. S-propyl ethylisobutylthiocarbamate Enough seeds were planted to give about thirty to fifty 4. S-isopropyl ethylisobutylthiocarbamate plants of each of the'weed species in each flat and the 5. S-butyl ethylisobutylthiocarbamate flats were watered after planting. The following day, 6. S-t-butyl ethylisobutylthiocarbamate each flat was sprayed at the rate of pounds in 80 gal- 7. S-sec-butyl ethylisobutylthiocarbamate lons of solution per acre of the given test composition. 8. S-isobutyl ethylisobutylthiocarbamate The flats were placed in a greenhouse at 80 F and wa-' 9. S-3-chloropropyl ethylisobutylthiocarbamate tered regularly. Two weeks later, the degree of weed l0 S-benzyl ethylisobutylthiocarbamate control was determined by comparing the amount of 11. S-methyl ethyl-t-butylthiocarbamate 20 germination and growth of each weed in the treated 12. S-ethyl ethyl-t-butylthiocarbamate flats with weeds in several untreated control flats. The 13. S-pr'opyl ethyl-t-butylthiocarbamate results of this test are reported in Table ll. 14. S-isopropyl ethyl-t-butylthiocarbamate An additional number of compounds of the invention 15. S-butyl'ethyl-t-butylthiocarbamate were tested in a similar manner on seeds of crabgrass, l6. S-benzyl ethyl-t-butylthiocarbamate foxtail, watergrass, wild oats, and pigweed. The results l7. S-rnetbyl methylamylthiocarbamate of this test are shown in Table III, using a scale of O to 18. S-ethyl methyiamylthiocarbamate 10 to show the rate of kill. 19. S-propyl methylamylthiocarbamate 20. S-butyl methylamylthiocarbamate 3 21. S-methyl ethylamylthiocarbamate O 22. S-ethyl ethylamylthiocarbamate TABLE m 23. S-propyl ethylamylthiocarbamate 24'. S-butyl ethylamylthiocarbamate 25. S-isopropyl methylamylthiocarbamate Compound Fmg wild i 26. S-isobutyl methylamylthiocarbamate Crabgrass tail grass Oats Wed 27. S sec butyl methylamylthiocarbamate :2 g 8 g g 2 28. S-t-butyl methylamylthiocarbamate l8 9 9 9 9 3 29. S-B-chloropropyl methylamylthiocarbamate 5g 3 g g g g 30. S-isopropyl ethylamylthiocarbamate 36 9 9 9 9 9 I 31. S-isobutylethylamylthiocarbamate 40 15 g g g g g 32. S sec butyl ethylamylthiocarbamate 33. S-t-butyl ethylamylthiocarbamate 34. S-3-chloropropyl ethylamylthiocarbamate 35. S-rnethyl butylisobutyl thiocarbamate As can be seen by the test results, the compounds of 36. S-ethyl butylisobutylthiocarbamate the invention are useful as herbicides. Several of the 37. S-propyl butylisobutylthiocarbamate compounds of the invention have also proven effective 38. S-isopropyl butylisobutylthiocarbamate in post-emergent treatment. The compounds may be 39. S-butyl butylisobutylthiocarbamate applied directly to the particular undesired plant spe- 40. S-isobutyl butylisobutylthiocarbamate cies or may be applied to 'a locus to be protected. In ei- 41. S sec butyl butylisobutylthiocarbamate ther event, it is, of course, necessary that the unwanted 42. 8-3 chloropropyl butylisobutylthiocarbamate species receive an effective dosage of amount, i.e., an 43. S-benzyl butylisobutylthiocarbamate amount sufficient to kill or retard growth.

44. S-3-chloropropyl allylbutylthiocarbamate The compounds are normally employed with a suit- 45. S-3-chloropropyl allylisobutylthiocarbamate able carrier and may be applied as a dust, spray, drench TABLE 11 Preemergenee activity rate: 20 lbs/a.

Crabgrass Foxtail Watcrgrass Red oats Pigwocd Mustard Curlcd dock (Digitaris (Sctaria [Echinochloa (Arena (Amarantkus (Brassica (Ramm: Compound number sanguinalz's) glauca) crusgallr) byzamina) retroflclus) juncca) crispus) =slight injury. =moderate injury. +++=severe injury or death.

or aerosol. The compounds thus may be applied in combination with solvents, diluents, various surface active agent (for example, detergents, soaps or other emulsifying or wetting agents, surface active clays), carrier media, adhesives, spreading agents, humectants and the like. They may also be combined with other biologically active compositions, including other herbicides, fungicides, bactericides and algaecides, insecticides, growth stimulators, acaricides, molluscicides, etc., as well as with fertilizers, soil modifiers, etc. The compounds of the invention may be used in combination with an inert carrier and a surface active or emulsifying agent and may also be applied in combination with other biologically active materials, in conjunction with a carrier and a surface active or emulsifying agent.

The solid and liquid formulations can be prepared by any of the conventional methods well known by those skilled in the art. Determination of the optimum effective concentration for a specific application is readily conducted by routine procedures, as will be apparent to those skilled in the art. As indicated, the amount applied in a given case will be an effective amount, i.e., an amount sufficient to give the type of control desired.

Various changes and modifications may be made without departing from the spirit and the scope of the invention described herein, as will be apparent to those skilled in the art to which it pertains.

I claim:

1. S-benzyl-N,N-ethylisobutylthiocarbamate. 

